1. Field of the Invention
This invention relates to a transmitter, a receiver, and a communication system and a communication method, and more particularly, is applicable to a radio network system for radio-transmitting digital data.
2. Description of the Related Art
The radio network system includes a system for radio-transmitting digital data such as image data between an AV (Audio Video) unit sets and a PC (Personal Computer) in a house or company. The radio network system realizes multi carrier transmission by using an orthogonal-frequency-division multiplexing system referred to as the orthogonal frequency division multiplex (OFDM) system as a modulation system.
In the case of this type of radio communication system, crosstalk may occur due to the fact that radio waves of another adjacent network reach the network of its own. Therefore, to avoid the crosstalk, a method is considered which avoids the fact that radio waves of other network are erroneously connected by adding a network ID (Identification) to radio waves to transmit it and identifying radio waves belonging to a network by the network ID. However, this method has a problem that the overhead occurs that the communications traffic of transmission data increases because it is necessary to add a network ID to the transmission data.
In view of the foregoing, an object of this invention is to provide a transmitter, a receiver, and a communication system and communication method capable of avoiding crosstalk with a simple structure.
The foregoing object and other objects of the invention have been achieved by the provision of a transmitter for transmitting input data after applying predetermined data processing to the input data. The transmitter comprises: error-detection-code addition means for adding an error detection code to the input data; logical operation means for generating transmission data by applying the logical operation between the output data output from the error-detection-code addition means and the identification-number data assigned to the transmitter to the transmission data; and transmission means for transmitting the transmission data after applying predetermined transmission processing to the transmission data.
Further, this invention provides a receiver for receiving a transmission signal transmitted from a transmitter. The receiver comprises: reception means for receiving the transmission signal; logical operation means for performing the logical operation between the reception data received by the reception means and the identification-number data assigned to the receiver; and error detection means for detecting an error in the output data in accordance with an error detection code added to the output data output from the logical operation means and disusing the output data when the error is detected.
Further, this invention provides a communication system for performing communication between a transmitter and a receiver. In the communication system, the transmitter has error-detection-code addition means for adding an error detection code to input data, first logical operation means for generating transmission data by performing the logical operation between the first output data output from the error-detection-code addition means and the first identification-number data assigned to the transmitter, and transmission means for transmitting a transmission signal generated by applying predetermined transmission processing to the transmission data. Also, in the communication system, the receiver has reception means for receiving the transmission signal, second logical operation means for performing the logical operation between reception data received by the reception means and the second identification-number data assigned to the receiver and same as the first identification-number data, and error detection means for detecting an error in the second output data in accordance with the error detection code added to the second output data output from the second logical operation means and disusing the second output data when the error is detected.
Further, this invention provides a communication method, which comprises the steps of: generating the first output data by adding an error detection code to input data; generating transmission data by performing the logical operation between the first output data and the first identification-number data; generating and transmitting a transmission signal by applying predetermined transmission processing to the transmission data; generating the second output data by performing the logical operation between reception data obtained by receiving the transmission signal and the second identification-number data same as the first identification-number data; and detecting an error in the second output data in accordance with an error detection code added to the second output data and disusing the second output data when the error is detected.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters.